Variable example embodiments relate to a semiconductor memory device, and more particularly, to a semiconductor memory device which stores refresh period information thereby adjusting a refresh period and a method of operating the same.
Along with rapid developments in capacities and speeds of semiconductor memory devices widely used in electronic devices, power consumption of semiconductor memory devices is increasing. Particularly, in case of portable electronic devices, it is very important to reduce power consumption of semiconductor memory devices in the portable electronic devices.
For example, a dynamic random access memory (DRAM), which is a volatile semiconductor memory device, is a memory device which stores data by using charges stored in a capacitor. Since charges stored in a capacitor may be leaked in various ways as time passes, a DRAM has a finite data retention characteristic. To resolve the finite data retention, it is necessary for a DRAM to refresh periodically to charge/discharge a capacitor according to data stored in the DRAM.
In general, if a refresh period becomes shorter, power consumption is increased in refreshing a DRAM. Therefore, it may help to reduce power consumption by adjusting a refresh period.